1. Field of the Invention
The present invention relates to a disc insertion preventive device which assures that when a disc apparatus is already loaded with a disc, another disc is prevented from being inserted into the apparatus.
2. Related Art
The disc apparatus records or reproduces information such as sound and pictures that stored in a disc, which is put on its turning table. There are various loading methods. For one example use is made of a reciprocating tray which carries a disc from the disc slot to the turning table or vice versa. For another example use is made of a pull-in mechanism which is responsive to insertion of a disc from the disc slot for gripping and pulling the disc toward the turning table in the housing.
A disc insertion preventive device according to the present invention is appropriate for use in the latter loading type. The user often tries to push a disc into the disc apparatus without making sure that it is not loaded with a disc. Then, the new disc hits the loaded disc so that they may be harmed or spoiled together. With a view to prevent such an incident some disc apparatuses are equipped with insertion preventive means.
JP-A-2001-331999, titled “Disc Device” shows a disc apparatus equipped with disc insertion preventive means, wherein it is allowed the sure dosing of an inserting and discharging member by an accidental insertion preventive member by making a movable range of the accidental insertion preventive member larger with respect to a descending distance of a movable base. This proposed structure is complicated and accordingly the manufacturing cost is high.
JP-A-2002-150652, titled “Slot-In Type Optical Disc Reproducing Device” uses various sensors to detect and reject any undesired disc even if it is inadvertently inserted in the disc apparatus. The insertion preventive mechanism cannot work even if a single sensor does not function well, and the optical detecting-and-rejecting unit is less reliable than the mechanical one.
JP-A-11-149688, titled “Disc Carrying Device” allows insertion of only a larger diameter disc while preventing insertion of a smaller diameter disc. The device is provided with a pair of belt to carry the large diameter disc into the device, and rotatable restriction pins on the insertion path to prevent insertion of the smaller diameter disc. However, the device is complicated in the structure, and in case a smaller disc is erroneously inserted, it is feared not to return the status before insertion. Further, the device has no means to prevent insertion of a second disc when a disc is already inserted in the device.
JP-A-01-227258, titled “Autoloading Disc Player” allows insertion of only a larger diameter disc, in which pair of upper and lower carrier rollers as well as two detective switches are provided on the insertion path of a disc. It is provided with a control means and command means to stop and spin the opposite way when a smaller disc is inserted. However, the device is complicated in the structure too, and it costs and is likely to cause incorrect actions and troubles since it uses electrical control means. Further, the device has no means to prevent insertion of a second disc.
In view of the above one object of the present invention is to provide a disc insertion preventive device which is simple in structure, still assuring that when a disc apparatus is already loaded with a disc, another disc is prevented from being inserted into the device, no matter what size or shape the subsequent disc may have.